Membrane type roofing systems are new to the industry and have created much interest among the trade. The importance to the future of the trade for single-ply roofing membranes is already becoming apparent. These systems presently constitute a low percentage of the total volume of roofing jobs being completed and it is felt that eventually the use of single-ply roofing systems will be the answer to a number of aggravating and costly problems.
Two factors dictating the trend towards a single-ply roofing system in the trade are the changes in roofing construction roof requirements along with the changing labor conditions.
In roughly four or five years, single-ply roofing systems in their many forms have captured fifteen to twenty-five percent of the commercial-industrial market with future projections calling for market shares of thirty-five to sixty percent.
As the use of single-ply roof membranes increases in the trade today, many systems are being devised for fixedly attaching the membrane to the roof. Such attaching systems may comprise the use of ballast laid on top of the loose single-ply membrane with the ballast comprising stone aggregates or other means of ballast. Another way of attaching the single-ply membrane to a roof may be the use of various types of adhesives spread between the membrane and the roofing insulation. The use of hot asphalt is also one of the methods presently being used on certain types of single-ply membranes. Contact adhesive is presently being used to adhere some single-ply membranes to the roofing system.
Other ways of fixing the single-ply membranes to a roof structure are a plurality of mechanical fasteners which are applied through the roof membrane and into the roof structure. This type of fastener then requires some type of application of cover material to be applied to the top of the fastener after it has been positioned through the membrane in order to avoid water problems inherent with the piercing of a membrane.
In the application of insulations to the roof deck of an industrial-type building, a special roof plate fastener is often used which is fixed in place with a special tool. This insulation fastener thereby serves to hold the insulation to the roof deck prior to the installation of a single-ply membrane which also must then be fastened to the roof structure. With the use of applicants' new and improved fastening device, the roof insulation fastener may be totally eliminated with the applicants' novel device functioning not only to hold the single-ply roof membrane on to the roof deck, but also to hold the roof insulation on the same deck. The savings in cost and labor for the previously used roof insulation fasteners then becomes apparent from a study of the applicants' invention as detailed in this application. In addition, applicants' fastening device lends itself well to the joining and sealing together of adjoining edges of adjacent membrane sections without the use of adhesives.
Many types of membranes are available today. The applicants' device may be used to fasten any of the three basic types, such as, the elastomeric, plastomeric and modified bitumen. Prior art fastening was determined by the particular type while the applicants' fastening is thereby universal for all types. Representative patents are U.S. Pat Nos. 1,886,708 to R. I. Markey; 1,896,130 to E. H. White; 4,057,095 to Y. Hirota; 4,063,393 to A. J. Toti and British Pat. No. 125,875 to Miller et al.